An automatic analysis device used for chemical analyses, such as a biochemical analyzer or an immunoassay analyzer, in clinical examination executes measurement by preparing a plurality of types of reagents in a reagent storage in accordance with items to be analyzed, and sucking a predetermined quantity of reagent from a reagent container in the reagent storage at a timing when the reagent is used, and then mixing the reagent with a sample. If the reagent stored in the reagent storage runs short during analysis, stopping the analysis at that stage and adding a reagent will reduce the efficiency of the analysis. Automatic analyzers are therefore designed so that if a shortage of reagent is likely, the device will warn the operator about the shortage, thus avoiding the situation that the operator will have to stop the device to add a reagent or replace the reagent with a new one during the analysis. Patent Document 1 describes an automatic analysis device with a configuration in which a loading system that permits reagent containers to be mounted therein is provided on a part of a fixed disk so that any of the reagent containers can be changed independently of the actuation status of the reagent fixed disk.